Cam controlled, diverse, co-acting doctors on a roller applicator



June 1955 J. E. SCHUESSLER CAM CONTROLLED, DIVERSE, C0-ACTING DOCTORS ON A ROLLER APPLICATOR 2 Sheets-Sheet 1 Filed Dec. 4, 1961 INVENTOR. JEROME E. SCHUESSLER AHorneys J. E. SCHUESSLER CAM CONTROLLED, DIVERSE, CO-ACTING June 1, 1965 DOCTORS on A ROLLER APPLICATOR 2 Sheets-Sheet 2 Filed Dec. 4, 1961 mm mm mm NM INVEN TOR. JEROME E. SCHUESSLER wwa w Attorneys United States Patent This invention .relates to method and apparatus for coating flat surfaces. More particularly, the invention relates to method and apparatus for applying thin, patterned layers of liquid to webs of material.

It is conventional to apply fluid material such as liquid paraffin and various adhesives to webs of paper, wood, plastic and the like. Frequently, as in fabrication of multi-ply paperboard, it is desirable to apply an adhesive in strips or various irregular patterns covering less than the extent of the surface of the paper plies. It has been suggested that special grooved, engraved or similarly irregular surfaced applicator rolls can be used to obtain these patterns. Also, spaced wiper fingers are used to selectively remove or wipe adhesive from the applicator roll before it contacts the material being coated.

These special rolls are rather expensive as compared to conventional smooth surfaced ones; replacement costs increase the expense and these special rolls are not as satisfactory as desired in obtaining clean edged strips and patterns. The wiper fingers, while satisfactory for many uses, often require complicated mounting structure, frequent manual adjustment and operator supervision.

Accordingly, it is an object of this invention to provide an improved method and apparatus for coating flat surfaces.

t is another object of this invention to provide an improved method and apparatus for applying thin patterned layers of fluid adhesive or liquid paraflin to strip material.

Another object of the invention is to provide novel doctor blade construction and a mounting therefor adapted for use in the practice of the method of this invention.

Most previous systems for obtaining the above discussed strips and patterns have required manual actuation and disengagement of the wiper finger, or other element, or that part which is instrumental in achieving the desired pattern. Such manual operation and the inherent operator supervision required is time consuming and results in machinery operating at much less than maximum output.

Accordingly, it is another object of this invention to provide a novel, automatic, integrated system for applying strips and patterns of liquid coating to the surfaces of strip material.

In one embodiment, apparatus for the practice of my method is comprised of a pair of rollers suitably supported in a horizontal position by auxiliary structure adapted to rotate them and to pass continuous strips of material to be coated in contact therewith. The lower roller or applicator has a bottom peripheral portion continuously passing through a bath of fluid to be applied to the material moving through the bite of the pair of rollers. Mounted adjacent that portion of the applicator roll emerging from the fluid bath is a pair of doctor blades. A first blade is adapted to remove excess material from a the roll and to assure even distribution of the remainder across the lateral extent of the roll. Mounted above this doctor blade is a second doctor blade. The second doctor blade is preferably a relatively thin yet flexible strip of blued spring steel having its rear portion fixed and its active edge adjacent the applicator roll. Structure mounted about the intermediate extent of this doctor blade is adapted to deform the blade to obtain a regular, low amplitude wavy configuration such that the active edge of the blade selectively wipes spaced portions of the peripheral surface of the applicator roll to obtain strips at intervals across the applicator roll.

"ice

The applicator roll and the second doctor blade are cooperatively interconnected through suitable circuiting whereby at periodic intervals the doctor blade is moved from contact with the applicator roll to obtain a cross hatched pattern of fluid on the roll.

Qther objects and further features and advantages of method and apparatus for the practice of my invention wiil become obvious to those skilled in the art from a study ofthe following detailed description with reference to the appended drawings in which like reference numerals are used to designate like parts in the several views. In

these drawings: I

FIG. 1 is a schematic side elevation of an installation for the practice of my'invention;

PEG. 1A is a schematic top elevation of a pair of microswitches in the arrangement of FIG. 1;

FIG. 2 is a fragmentary rear elevation in partial section of the arrangement of FIG. 1;

FIG. 3 is a fragmentary top view of one of the doctor blades of the arrangement of FIG. 1;

FIG. 4 is a fragmentary perspective view of a second doctor blade of the arrangementof FIG. 1 exaggerated to more clearly show characteristics thereof;

FIG. 5 is a schematic illustration of a typical adhesive pattern obtainable with the apparatus of FIGS. 1 through 4; and

FIG. 6 is a typical paraflin pattern on a paperboard box blank.

The apparatus of FIG. 1 includes an applicator roller 11 rotatably carried on a shaft 13 in spaced but proximate relation to an upper roller it rotatably carried on a shaft 12. The conventional auxiliary support parts, motors and the like for this apparatus-and for turning shafts 13 and 12 are partially shown in FIG. 2, but details thereof are not shown in order to maintain drawing simplicity.

A table 14 extends forwardly to adjacent the bite of rollers it) and 11, which rotate in the direction indicated by the arrows, and is adapted to guide a web or sheet of material it? moving under the influence of feed roller 15 which is rotatably carried on a shaft 16. Roller 15 is adapted for rotation at the same peripheral speed as the peripheral speed of rollers 10 and 11 to provide smooth controlled feeding of strip material to the bite of these latter rollers.

The lower peripheral portion of roller 11. is conven tionally adjacent a source of fluid or in a bath of fluid to be applied to the strip material. In FIG. 1 this has been schematically indicated by the dashed line receptacle 1%. In the case of paraffin application, a smaller doctor roller meters fluid to the applicator roller.

The outer end of shaft 13 is reduced or turned down and passes through bearings 13A on frame 13B and into the magnetic clutch 19. Details of the clutch are not hown since they are conventional. Usually, the clutch is connected to a power source which energizes a coil which in turn creates a high density magnetic field. The field attracts an armature to a rotor creating a smooth, positive, shock-free start of a driven hub. To disengage a driven load or disconnect the drive hub, the coil is deenergized, thus separating the armature and driven member from the rotor. With the magnetic clutch of FIG. 1 the driven -.ember is an external gear Ztl. The gear 26 is adapted to mesh with the peripheral gear teeth on the control plate 21 which will be described in more detail hereafter.

Above'that portion of roll ll emerging from receptacle 18 is a pair of doctor blades 22. and 23. Doctor blade 22 (see FIG. 3) is a thin sheet of rigid material having its active edge slotted to provide a plurality of extending teeth 22A and depressions 225. The lateral dimension of the teeth and slots are equal. This doctor blade is arranged to wipe excessive material from the roller 11 as it emerges from the bath of fluid. The wiped and unwiped 2t? has a recess 27 extending through its lateral extent.

Passing through block 25 at spaced intervals are a plurality of thumb screws 28. The plurality of thumb screws 2%; are. adapted for applying varying degrees of pressure across the lateral extent of blade and together with the mouth of the blocks through which the blade extends are arranged to induce a small amplitudewavy configuration in the leading or active edge of the blade 23. Such a configuration is shown in FIG. 4 but it has been exaggerated for purposes of explanation. in operation, the amplitude will be on the order of.0.010 to 0.020 of an inch. The mounting blocks 25 and 26 and associated structure are adapted to maintain the leading edge of the doctor blade 23 in proximate relation to the periphery of the applicator roller. When the thumb screws 28 have been adjusted as desired and the regular, small amplitude wavy configuration of the leading edge of blade 23 results, the troughs of the wavy leading edge flatten slightly at points of roller contact and wipe spaced portions of the roller thereby providing a strip pattern of fluid for coating the undersurface of the strip material 17. The spacing of the waves in the leading edge of doctor blade 23 is easily adjusted by operator variation in the relative pressure exerted by thumb screws 28 on the upper surface of the blade.

The foregoing arrangement and the novel operation of doctor blade 23 may be utilized in apparatus for applying fluid adhesive to strips or webs of paper used in the fabrication of paperboard materials. Further, it may be utilized in applying liquid parafiin to webs of material. The relative width. of the strips of adhesive or parafiin which are applied is very easily varied and accurately controlled by simple manipulation of the thumb screws 28 as above described.

Sometimes, however, it is desirable to obtain a pattern of discontinuous wiped strips such as the pattern shown in FIG. 5, or in FIG. 6. To this end, I include a novel, integrated, control system for automatically obtaining the pattern. This arrangement includes the spring microswitch 4t) having a downwardly extending coil spring actuator 41 adapted to be tripped by the forward movement of web l? as indicated by the dotted lines in FIG. 1 to in turn energize the magnetic clutch. The magnetic clutch drives the control plate 21. Control plate 21 is mounted for rotation on a shaft 42 and has a plurality of lugs or cars 4-3 releasably attached at intervals around its peripheral extent. For convenience in the following description, these lugs have been labeled A, B, C, D, E and F. Mounted beneath the control plate 21 and its lugs A-F is a pair of microswitches 44 and 44a. The top view of FIG. 1A schematically indicates the relative side by side positioning of the actuators 45 and 46 of the microswitches 44a and 44-.

With this positioning, each of the lugs A-F is adapted for periodic contact with actuator 46. Lug A has a laterally extending portion which is adapted to trip the actuator 45. None of the other lugs contacts actuator 45. When lug A contacts actuator 45 the system is shut ofi. When a following piece of material 17 passes microswitch it causing actuation of clutch 19 with commensurate rotation of control plate 21, lug A contacts actuator 46. This causes operation of solenoid 47 retracting arm 48. Solenoid 47 has an extending rod 48 pivotally interconnected with the bell crank lever 49. An intermediate boss 49a on the bell crank, at its knee, is pivotally interconnected with the mounting blocks 25 and 26 holding the doctor blade 23. In the position shown in FIG. 1 with the rod 48 in an extended position, the blade 23 is in operative wiping Contact with roll 11. However, when the rod 43 is retracted the blade 23 is lifted from contact with the roll 11. Thus, as lug A passes actuator 46 the rod 48 is retracted and the blade 23 moves from contact with the periphery of roil 11. As rotation of the control plate continues, lug B contacts microswitch 46 causing deenergization of solenoid 47 and extension of arm 48 under the influence of spring 72, placing doctor blade 23 in surface contact with roll 11.

When the doctor blade 23 is lifted from contact with the roll 11 the lateral strips of adhesive, generally indicated by 5b in FIG. 5, result. In the intermediate or blade contact position, the longitudinal strips of adhesive 51 and blank spaces 52 result. Thus, referring again to the control plate and its lugs A through F, as lug A passes actuator lever 46 the doctor blade is moved out of contact with the roll. The following contact of lug B causes release of the solenoid rod 48, moving the blade to contact with roll 11 under influence of spring '72. As lug C contacts actuator lever 4d, the blade breaks contact with the roll, D repiaces it, E removes it, and F again replaces it in contact with the roll.

Continued rotation brings lug A back in contact with actuator lever 35 thereby stopping operation until the next strip of material 17 again actuates microswitch it) and thus the magnetic clutch 19 to repeat the operation.

To obtain the pattern arrangement of FIG. 6, the lugs are rearranged to provide a wide continuous paraffin strip 7%, flaps 71 likewise being coated, but flaps 72 being clean since they are the sealing or closing portions. The box blank which results may thereafter be folded along the dotted lines, all waxed or parafiin coated portions being interior walls, and the clean flaps 72 being used as sealing or closing flaps.

Continuing with the description of the arrangement of parts, the opposite end ofbell crank lever 49 is interconnected through boss 55 with the spring loaded arm 55. The eyelet at the opposite end of rod 56 is mounted on a shaft 32. A second rod 57 extends from this same shaft 32 and is interconnected through boss 58 with a second crank arm 59 carrying a boss 6% which is interconnected with doctor blade 22. The eyelets of rods 56 and 57 are larger in diameter than shaft 32 and arranged "to slip easily over its surface. Two circumferential grooves are formed adjacent the end of shaft 32 in which seat the eyelets of rods 56 and 57. Rod 56 is maintained therein by the action of the compressed spring 72 on arm 56, and rod 57 is held in position by relative tightening of nut 58A. 7

In order to limit the downward range of movement of blade 23, a jackscrew 61A is included. By turning thumb screw 61 (the upper end of which bears against the bottom of mounting block 26) the downward range of movement of the pair of blocks and the included blade 23 may be varied.

Each of the lugs A through F includes a screw 65. By suitable loosening and tightening of the screws 65 the relative spacing of the lugs can be varied, thereby providing variation in the adhesive pattern.

As above noted, a spring 72 carried by rod 56 maintains the eyelet of rod 56 in operative contact with shaft 32 as well as holding the blade 23 in roller contact when the solenoid is deenergized. By loosening the screw '70 and moving the collar 71 up and down rod 56, the relative compression in spring 72 may be varied as desired.

It is, of course, to be understood that the arrangements shown in the drawings are merely exemplary and that the true measure of the spirit and scope of the invention is to be as defined. in the hereafter appended claims.

Having thus described my invention in detail and with sufficient particularity as to enable those skilled in the art to practice it, what I desire to have protected by Letters Patent is set forth in the following claims.

I claim:

I. In apparatus for applying a patterned fluid coating to a web of material, including an upper roller and a lower applicator roller in spaced but proximate relation to each other, and the applicator roller being in association with a source of fluid to be applied, the improvement comprising first means to selectively wipe spaced portions of the applicator roller to selectively remove fluid including a flexible strip having a straight continuous edge and adjustable means holding the strip in proximate relation to the periphery of the applicator roller moving out of contact with its associated source of fluid, means inclusive of upper and lower blocks mounted on the rear portion of said strip and spaced thumbscrews across the lateral extent of said strip adapted to impart a regular wavy configuration to the leading edge of the strip by pressure of the thumbscrews on the strip, an integrated, automatic control system including second means arranged to selectively move the strip from wiping contact with the applicator roller, clutch means arranged to selectively rotate with the applicator roller, adjustable cam means in driven engagement with the clutch means, first switch means adapted to cause engagement of the clutch means to drive the cam means when a web to be coated approaches the bite of the upper roller and the lower applicator roller, and second switch means selectively actuated by the cam means, said second switch means adapted to selectively actuate said second means causing the strip to be selectively moved from wiping contact with the applicator roller.

2. The apparatus of claim 1 in which the cam means is a cylindrical plate having a plurality of lugs peripherally attached at predetermined spaced intervals and arranged to progressively, selectively energize and de-energize the second switch means.

3. The apparatus of claim 2 in which a first of the lugs is adapted to tie-energize the clutch after a single rotation of the plate.

References Cited by the Examiner UNITED STATES PATENTS 1,741,211 12/ 29 Vallier.

1,848,591 *3/32 Wood 101-350 X 1,932,989 10/33 Rider 1l8--204 X 2,097,428 11/37 Bergstein 118204 2,605,740 8/52 Taylor et al. 118236 2,765,766 10/56 Davis et al. 118-211 X 2,776,224 1/57 Cote 1l8-1 X 2,873,717 2/59 Griffin et a1. 1l8-261 X 2,925,800 2/60 Wassem 1181 3,037,451 6/62 Davis 118261 X 3,052,210 9/62 Hughes 118211 X RICHARD D. NEVIUS, Primary Examiner. 

1. IN APPARATUS FOR APPLYING A PATTERNED FLUID COACTING TO A WEB OF MATERIAL, INCLUDING AN UPPER ROLLER AND A LOWER APPLICATOR ROLLER IS SPACED BUT PROXIMATE RELATION TO EACH OTHER, AND THE APPLICATOR ROLLER BEING IN ASSOCIATION WITH A SOURCE OF FLUID TO BE APPLIED, THE IMPROVEMENT COMPRISING FIRST MEANS TO SELECTIVELY WIPE SPACED PORTIONS OF THE APPLICATOR ROLLER TO SELECTIVELY REMOVE FLUID INCLUDING A FLEXIBLE STRIP HAVING A STRAIGHT CONTINUOUS EDGE AND ADJUSTABLE MEANS HOLDING THE STRIP IN PROXIMATE RELATION TO THE PERIPHERY OF THE APPLICATOR ROLLER MOVING OUT OF CONTACT WITH ITS ASSOCIATED SOURCE OF FLUID, MEANS INCLUSIVE OF UPPER AND LOWER BLOCKS MOUNTED ON THE REAR PORTION OF SAID STRIP AND SPACED THUMBSCREWS ACROSS THE LATERAL EXTENT OF SAID STRIP ADAPTED TO IMPART A REGULAR WAVY CONFIGURATION TO THE LEADING EDGE OF THE STRIP BY PRESSURE OF THE THUMBSCREWS ON THE STRIP, AN INTERGRATED, AUTOMATIC CONTROL SYSTEM INCLUDING SECOND MEANS ARRANGED TO SELECTIVELY MOVE THE STRIP FROM WIPING CONTACT WITH THE APPLICATOR ROLLER, CLUTCH MEANS ARRANGED TO SELECTIVELY ROTATE WITH THE APPLICATOR ROLLER, ADJUSTABLE CAM MEANS IN DRIVEN ENGAGEMENT WITH THE CLUTCH MEANS, FIRST SWITCH MEANS ADAPTED TO CAUSE ENGAGEMENT OF THE CLUTCH MEANS TO DRIVE THE CAM MEANS WHEN A WEB TO BE COATED APPROACHES THE BITE OF THE UPPER ROLLER AND THE LOWER APPLICATOR ROLLER, AND SECOND SWITCH MEANS SELECTIVELY ACTUATED BY THE CAM MEANS, SAID SECOND SWITCH MEANS ADAPTED TO SELECTIVELY ACTUATE SAID SECOND MEANS CAUSING THE STRIP TO BE SELECTIVELY MOVED FROM WIPING CONTACT WITH THE APPLICATOR ROLLER. 